This invention relates to an electrostatographic printer or copier, and more particularly concerns a cleaning apparatus and method for cleaning triboelectric negative toner without the use of a preclean corotron.
For DAD (Discharge Area Development) and image quality, triboelectric negative toners are being used with greater frequency in electrostatographic printers and copiers. These toners are designed to be triboelectric negative, inherently, and charge negatively with a positive developer carrier. This triboelectric negative charge of the toner particles affects effective cleaning of these particles from the imaging surface.
The following disclosures may be relevant to various aspects of the present invention and may be briefly summarized as follows:
U.S. Pat. No. 5,257,079 to Lange et al. discloses a cleaning brush electrically biased with an alternating current removes discharged particles from an imaging surface. The particles on the imaging surface are discharged by a corona generating device. A second cleaning device including an insulative brush, a conductive brush or a blade, located upstream of the first mentioned brush, in the direction of movement of the imaging surface, further removes redeposited particles therefrom.
U.S. Pat. No. 4,545,669 to Hays et al. discloses an apparatus for simultaneously charging, exposing, and developing imaging numbers at low voltages which comprises a semi-transparent deflected flexible imaging member, an electronic imaging source means, a light beam deflector member, a means, containing magnets therein, a development roll means containing magnets therein, a voltage source means for sensitizing roll means, a voltage source for the development roll means, a developer supply reservoir containing conductive developer particles therein comprised of insulating toner resin particles and conductive carrier particles, a sensitizing nip situated between the flexible imaging member and the sensitizing roll, a development nip situated between the imaging member and the development roller, the sensitizing roll means and development roll means moving in the same direction o movement as the semi-transparent deflected flexible imaging member, the voltage being generated by the voltage source with the sensitizing nip being of an opposite polarity of the voltage generated by the voltage source for the development roller, wherein an electric field of a predetermined polarity is established between the semi-transparent deflected flexible imaging member ant the sensitizing roll means, which field exert in the sensitizing roll means, which field exerts in the sensitizing nip an electrostatic force on the charged toner particles causing these particles to uniformly migrate toward the imaging member, subsequently subjecting the deflected flexible imaging member to the electronic image source whereby the electrostatic force exerted on the toner particles adjacent the light struck areas of the flexible imaging member are increased thereby causing toner particles to be deposited on the deflected flexible imaging member, and wherein toner particles are removed from the deflected flexible imaging member in areas not exposed to light by the development roll and developed in the areas exposed to light.